Leadless Pacemaker Systems Research Articles

Chronic Wireless Communication Between Dual-Chamber Leadless Pacemaker Devices

BackgroundAveir™ DR (Abbott) is a dual-chamber leadless pacemaker (LP) system with distinct atrial and ventricular LPs (ALP, VLP) that communicate wirelessly to deliver atrioventricular synchronous pacing. Success rates of these implant-to-implant (i2i™) transmissions have not been systematically evaluated. ObjectiveTo evaluate chronic i2i success rates in a clinical setting. MethodsPatients meeting standard dual-chamber pacing indications were enrolled and implanted with dual-chamber LP systems as part of a prospective, international clinical trial (“Aveir DR i2i Study”). The percent of successful i2i transmissions from ALP-to-VLP (A-to-V) and VLP-to-ALP (V-to-A) were interrogated from LPs in de novo patients using the device programmer at implant, discharge, and at 1-, 3-, and 6-months post-implant (1M, 3M, 6M). Results399 patients completed device implant and i2i diagnostic interrogation (62% male; age 69 years; 65% sinus node dysfunction, 32% AV block). Median A-to-V and V-to-A i2i success rates exceeded 90% of beats at all time-points from implant to 6M. The minority of patients with A-to-V or V-to-A i2i success in <70% of beats at implant (A-to-V: 19% of patients, V-to-A: 31% of patients) showed roughly 40% improvement by 1M, with this minority dropping to roughly 5% of patients by 6M. Improvement in i2i communication success may be attributed to reprogramming of i2i setting levels, natural changes in dominant posture, and device stabilization. ConclusionWireless implant-to-implant communication in the new dual-chamber leadless pacemaker system demonstrated successful transmissions in >90% of beats throughout the 6-month evaluation period. Communication success improved significantly over time post-implant for specific subgroups.

Atrioventricular Synchrony Delivered by a Dual-Chamber Leadless Pacemaker System.

A dual-chamber leadless pacemaker system has been designed for atrioventricular synchronous pacing using wireless, beat-to-beat, implant-to-implant (i2i) communication between distinct atrial and ventricular leadless pacemakers. The atrioventricular synchrony achieved across various ambulatory scenarios has yet to be systematically evaluated. A prospective, single-arm, unblinded, multicenter, international clinical trial of the leadless pacemaker system was conducted in patients with a conventional dual-chamber pacing indication enrolled from February 2022 to March 2023. Leadless pacemaker systems were implanted, and 12-lead Holter electrocardiographic recordings were collected 3 months after implantation over various postures/activities: sitting, supine, left lateral recumbent, right lateral recumbent, standing, normal walk, and fast walk. An independent Holter core laboratory performed a manual adjudication of the percent of atrioventricular synchronous beats using the standard 300-millisecond PR interval limit. Atrium-to-ventricle and ventricle-to-atrium i2i communication success rates were also assessed. Post hoc summary statistics describing the relationships between atrioventricular synchrony and i2i success, posture/activity, implantation indication, atrioventricular event, and heart rate were calculated. In the evaluable population (n=384 of 464 enrolled [83%]; 61% male; age, 70 years; weight, 82 kg; 60% ejection fraction; 95% of beats evaluable), the mean atrioventricular synchrony of 98% of beats observed across all postures using the standard 300-millisecond limit was greater than both atrial-to-ventricular i2i (94%) and ventricular-to-atrial i2i (94%; P<0.001), exceeding both i2i values in 95% of patients. Atrioventricular synchrony was achieved in >95% of evaluable beats across all postures/activities, implantation indications, atrioventricular paced/sensed event combinations, and heart rate ranges (including >100 bpm). This dual-chamber leadless pacemaker system demonstrated atrioventricular synchrony in 98% of evaluable beats at 3 months after implantation. Atrioventricular synchrony was maintained across postures/activities and remained robust for heart rates >100 bpm.

Transfemoral leadless pacemaker implantation after tricuspid valve surgery and intervention

Abstract Background and Purpose Pacemaker (PM) implantation after surgical or transcatheter tricuspid valve (TV) repair or replacement may be challenging. Transcatheter leadless pacemaker (LPM) implantation has become a routine procedure and is frequently adopted in patients without the need for an atrial lead, in cases with cardiac implantable device infection or in patients with marked comorbidities. The use of LPM in patients with previous TV repair or replacement has only been described in singular cases in literature. We present our single center experience of LPM implantation after TV repair. Methods Patients with a history of TV repair or replacement who underwent LPM in our institution between 01/2020 and 11/2023 were retrospectively analyzed. All patients underwent routine clinical follow-up investigations including LPM interrogation and transthoracic echocardiography to assess for TV status. For LPM implantation right anterior oblique (RAO) and left anterior oblique (LAO) caudal fluoroscopy projections were utilized to enable LPM device passage across the TV. Results The study population consisted of 10 patients (9 females, mean age 74.0±10.0 years). Two patients had a history of surgical TV annuloplasty repair and two patients a history of surgical valve replacement, four patients of transcatheter TV repair (one through the mitral clip), one patient of transcatheter valve-in-ring bio prosthesis implantation prosthesis after previous surgical ring deployment and one patient transcatheter TV replacement (Figure1). All patients suffered from permanent atrial fibrillation previous to implantation procedures. Three patients were on chronic hemodialysis therapy before LPM implantation. LPM systems were successfully implanted in all cases with a mean procedure time of 43.5±26.5 minutes and a mean fluoroscopy time of 5.9±5.5 minutes and a radiation dose of 1148,7±1424,9 cGy·cm2. For fluoroscopically guided TV crossing a mean LAO angle of 43.6±14.1° (range 22 to 53°) and caudal angle of 8.5±6.9° (range 0 to 20°) was utilized (Figure 2). The LPM device was positioned in the first positioning attempt in a right ventricular high septal localization in 8 cases. Mean pacing threshold was 0.36±0.07 V at 0.25 ms, with a mean sensing amplitude of 10.5±2.9 mV and a mean of 853±324 Ohms pacing impedance. No periprocedural complications occurred. Mean duration of follow-up was 8.1±9.2 months. There were no newly developed TV regurgitations noted. Pacing thresholds (0.37±0.1 V/0.25 ms), sensing amplitude (11.8±4.5 mV) as well as pacing impedances (865±365 Ohms) remained stable until the last follow-up investigation. Conclusion LPM implantation was feasible in patients with a history of TV repair or replacement. LPM implantation was safe and effective in various modalities of TV repair. LPM may be an alternative to conventional pacemaker implantations as well as surgical lead placement in selected patients.Figure 1.Figure 2.

Reduced-Size Antenna for Leadless Cardiac Pacemaker

The advancement in technology led to the development of leadless cardiac pacemaker (LCP) systems that resolved the issues that arise due to the use of leads in the conventional pacemakers (CP). However, the compact size of the LCP system also requires a miniaturized antenna that can fit inside the limited space of the LCP. Therefore, this study was conducted to propose and design a reduced-size antenna that operates at 2.4 GHz. An implantable antenna with a footprint of 4.00 5.00 0.50 mm was designed using CST Microwave Studio (student version). An LCP system was integrated with the antenna and simulated inside the heart tissue model to evaluate the performance of the antenna. Based on the S11 parameter, the antenna was further optimized, and the coaxial-feed cable position was offset until the impedance matching was achieved for the resonant frequency to be at 2.4 GHz. The antenna exhibited good performance with a S11 of less than -10 dB at 2.4 GHz. In addition, the proposed antenna satisfies the requirements of LCP with limited space. Therefore, the proposed antenna is envisaged to be implemented for LCP systems.

Leadless and symbiotic cardiac pacemakers; as an alternative to conventional pacemakers

There have been considerable advancements in technology since the first permanent pacemaker was implanted in 1960. A subcutaneous generator and battery module are connected to one or more endocardial leads in the conventional pacemaker implantation. Despite their proven efficiency, traditional permanent pacemakers have a number of drawbacks their use has been linked to potential complications during implantation procedure and also during follow-up period; among the most notable ones are lead malfunction, limited battery life, and device-related infections. Therefore, there had been tremendous efforts to avoid such complications and to increase battery life. In this Review, we explore new electronic devices, leadless pacemaker systems and symbiotic cardiac pacemakers, designed to avoid these current limitations.

Quantitative and Qualitative Assessment of Adhesive Thrombo-Fibrotic Lead Encapsulations (TFLE) of Pacemaker and ICD Leads in Arrhythmia Patients-A Post Mortem Study.

The demand for cardiac implantable electronic devices for arrhythmia therapy is still unabated and rising. Despite onward optimizations, lead-related problems such as infections or fractures often necessitate lead extraction. Due to adhesive thrombo-fibrotic lead encapsulations (TFLE) transvenous lead extraction is challenging and risky. However, knowledge on TFLEs and possible correlations with technical lead parameters and dwelling time (DT) were hitherto insufficiently studied. Therefore, we analyzed TFLEs of 62 lead from 35 body donor corpses to gain information for a potential lead design optimization. We examined both TFLE topography on the basis on anatomical landmarks and histo-morphological TFLE characteristics by means of histological paraffin sections and scanning electron microscopy of decellularized samples. The macroscopic analysis revealed that all leads were affected by TFLEs, mainly in the lead bearing veins. Half (47.2%) of the right-ventricular leads possessed adhesions to the tricuspid valve. On average, 49.9 ± 21.8% of the intravascular lead length was covered by TFLE of which 82.8 ± 16.2% were adhesive wall bindings (WB). The discrete TFLEs with at least one WB portion had a mean length of 95.0 ± 64.3 mm and a maximum of 200 mm. Neither sex, DT nor certain technical lead parameters showed distinct tendencies to promote or prevent TFLE. TFLE formation seems to start early in the first 1–2 weeks after implantation. The degree of fibrotization of the TFLE, starting with a thrombus, was reflected by the amount of compacted collagenous fibers and likewise largely independent from DT. TFLE thickness often reached several hundred micrometers. Calcifications were occasionally seen and appeared irregularly along the TFLE sheath. Leadless pacemaker systems have the advantage to overcome the problem with TFLEs but hold their own specific risks and limitations which are not fully known yet.

Update in Cardiac Pacing.

Initial efforts to artificially stimulate the heart were borne out of a necessity to prevent catastrophic bradycardic events. The initial pacemaker systems were large, bulky external devices. However, advancements in technology allowed for the development of internally powered, fully implantable devices. Further advancements resulted in more complex, programmable devices, but the overall systems have remained largely unchanged for more than 50 years. The most recent advancements in the field have represented fundamental paradigm shifts in both pacemaker design and the approach to cardiac pacing. These efforts have focused on reducing and eliminating hardware to reduce the risk of complications and to focus on improving cardiac efficiency to improve clinical outcomes. In this article, the authors explore these advances including leadless pacemaker systems, permanent His bundle pacing and advances in the field of cardiac resynchronisation therapy.

Design and Analysis of a Compact-Sized Multiband Spiral-Shaped Implantable Antenna for Scalp Implantable and Leadless Pacemaker Systems

In this communication, a multiband spiral-shaped implantable antenna for scalp implantation and leadless pacemaker systems is presented. The proposed antenna has the following operational bands: medical implanted communication service (MICS) (402–405 MHz), industrial, scientific, and medical (ISM) (433.1–434.8 MHz and 2400–2483.5 MHz), and midfield (1520–1693 MHz). The recommended antenna system consists of two implantable devices: a flat-type scalp implantable device and a capsule-type leadless pacemaker. In each device, the antenna is integrated with controlling electronic components and a battery. The proposed antenna has a compact size of 17.15 mm3 (7 mm $\times6.5$ mm $\times0.377$ mm). A significant size reduction for the antenna is achieved by using a spiral-shaped radiator with two symmetrical arms and introducing an open-end slot in the ground. The key features of the proposed antenna are its compact size, vialess ground plane, multibands, wide bandwidth, and satisfactory gain values compared to other implantable antennas. The maximum realized gain values of the proposed structure are −30.5, −30, −22.6, and −18.2 dBi at 402, 433, 1600, and 2450 MHz, respectively. The design and analysis of the antenna are carried out with simulators, based on the finite-element method (FEM) and the finite-difference time domain (FDTD). The performance of the antenna is experimentally validated using a saline solution and minced pork muscles. Moreover, the specific absorption rate (SAR) distributions at all frequencies induced by the implantable antenna are evaluated. In addition, a wireless communication link budget is calculated to specify the range for biotelemetry at data rates of 7 and 100 kb/s.

Potential mechanisms of endothelialisation in individuals implanted with a leadless pacemaker systems: An experimental in vitro study

BackgroundLeadless pacemaker technology is a promising upcoming field in clinical rhythmology. Today, the most commonly used system in the clinical setting is the Micra™ leadless pacemaker system (Medtronic).In autopsies of patients who witnessed non-pacemaker associated death, unexpected ingrowth/encapsulation within the wall of the right ventricle was reported. The occurrence of a complete encapsulation was not expected and the process of endothelialisation remains unclear. We hypothesized, that a local inflammatory response might be the cause of these findings. The aim of our experimental in-vitro study was to investigate the effect of the Micra™ system and its single components on inflammatory processes. MethodsFor this purpose, whole Micra™ pacemakers were incubated in heparin plasma from 25 healthy volunteers for 48 h at 37 °C. Furthermore, 1 g gold, steel, titanium, tungsten and nitinol wires were incubated in heparin plasma for 48 h at 37 °C as well (n = 10).To detect eventual inflammatory processes, interleukin- (IL) 1β, IL-6, and tumor necrosis factor alpha (TNF-α), the chemokine IL-8 were measured using enzyme-linked immunosorbent assay (ELISA). Additionally, the level of transforming growth factor beta 1 (TGF-β1) and vascular endothelial growth factor (VEGF) were analysed. ResultsELISA analyses showed that the whole Micra system leads to a significant increase in the inflammatory cytokine IL-6 which correlates with the data gained by the incubation of whole blood with the different wires. In particular, 0.5 g of tungsten showed a significant rise of IL-6 which could also be found for IL-1β and IL-8. ConclusionsThe in vitro study of the Micra system showed that the material composition led to an onset of inflammatory processes in whole blood. Consequently, one may speculate that the composition of Micra pacemaker may have a local inflammatory, though subclinical, effects in patients implanted with a Micra™ pacemakers.

Neue innovative Schrittmachersysteme – Kabellose und subkutane Implantate

Conventional transvenous pacemaker and ICD-therapy is associated with significant lead- and pocket-related problems. Leadless pacemaker and subcutaneous ICD (S-ICD) therapies are innovative technologies, that avoid these complications. To date two leadless pacemaker systems have been implanted percutaneously for isolated right ventricular pacing, the Nanostim™ and the Micra™ device. The S-ICD represents an alternative to the transvenous ICD for primary and secondary prevention of sudden cardiac death. New multicomponent leadless pacemakers, as well as the combination of leadless pacemaker and S-ICD, are promising therapeutic options in the future. This review describes the state of the art of leadless pacing and S-ICD-therapy.

Meta-analysis of the incidence of lead dislodgement with conventional and leadless pacemaker systems.

Leadless cardiac pacemaker (LCP) implantation using a transcatheter was recently developed to avoid pocket- and lead-related complications. Although a LCP has an active fixation mechanism using tines or a helix, LCP and lead dislodgement issues remain a major safety concern for patients. This article reviews the literature to determine the incidence of lead and LCP dislodgement. A total of 18 studies which included 17,321 patients undergoing conventional single- or dual-chamber pacemaker implantation and three studies which included 2,116 patients undergoing LCP device implantation were reviewed. The incidence of lead dislodgement ranged from 1% to 2.69% in individual studies with a mean of 1.63%, weighted mean of 1.71%, and median of 1.60 %. There was a relatively higher lead dislodgement rate between atrial and ventricular electrodes (odds ratio [OR], 3.56; 95% confidence interval [CI], 1.9-6.70; P=0.6; I2 =0%), and between magnetic resonance imaging conditional and conventional leads (OR, 2.79; 95% CI, 1.30-5.99; P=0.16; I2 =46%). The use of active fixation leads (OR, 1.06; 95% CI, 0.66-1.70; P=0.29; I2 =20%) showed no significant difference in dislodgement risk compared to passive fixation leads. The incidence of LCP device dislodgement was 0%, 0.13%, and 1% in three leadless pacemaker studies. The incidence rates of conventional pacemaker lead dislodgement vary in individual studies with an overall high incidence. Use of the currently available LCP systems appears to result in a lower rate of device dislodgement. This may reflect the effectiveness of this novel technology and the fixation design of LCP devices.

Visualization and appearance of artifacts of leadless pacemaker systems in cardiac MRI : An experimental ex vivo study.

SummaryBackgroundLeadless pacemaker systems are an important upcoming device in clinical rhythmology. Currently two different products are available with the Micra system (Medtronic) being the most used in the clinical setting to date. The possibility to perform magnetic resonance imaging (MRI) is an important feature of modern pacemaker devices. Even though the Micra system is suitable for MRI, little is yet known about its impact on artifacts within the images.ObjectiveThe aim of our ex vivo study was to perform cardiac MRI to quantify the artifacts and to evaluate if artifacts limit or inhibit the assessment of the surrounding myocardium.MethodsAfter ex vivo implantation of the leadless pacemaker (LP) in a porcine model, hearts were filled with saline solution and fixed on wooden sticks on a plastic container. The model was examined at 1.5 T and at 3 T using conventional sequences and T2 mapping sequences. In addition, conventional X‑rays and computed tomography (CT) scans were performed.ResultsCorrect implantation of the LP could be performed in all hearts. In almost all MRI sequences the right ventricle and the septal region surrounding the (LP) were altered by an artifact and therefore would sustain limited assessment; however, the rest of the myocardium remained free of artifacts and evaluable for common radiologic diagnoses. A characteristic shamrock-shaped artifact was generated which appeared to be even more intense in magnitude and brightness when using 3 T compared to 1.5 T.ConclusionThe use of the Micra system in cardiac MRI appeared to be feasible. In our opinion, it will still be possible to make important clinical cardiac MRI diagnoses (the detection of major ischemic areas or inflammatory processes) in patients using the Micra system. We suggest the use of 1.5 T as the preferred method in clinical practice.

Leadless Pacemaker Technologies: Patient Selection, Approach, and Outcomes

Leadless cardiac pacemakers have recently entered clinical use for patients requiring single ventricular chamber pacing only. Two leadless systems have been utilized, the Nanostim leadless cardiac pacemaker and the Micra transcatheter pacing system. While currently limited to only a minority of pacemaker eligible patients, technical hurdles are expected to be overcome which will allow this technology to reach a much broader population. This review discusses the patient population for which these devices are indicated, the approach to device implantation and retrieval, and ongoing data on their long-term use. Two major non-randomized clinical trials investigating the Nanostim and Micra leadless pacemaker systems were published in the New England Journal of Medicine in 2015 and 2016, respectively, with implant success rates of the active and passive fixation devices of 95.8 and 99.2%, respectively. The Nanostim and Micra demonstrated efficacy and safety, with major complication rates of 6.7 and 4% at 6 months, respectively, comparing favorably to historical transvenous pacemaker controls. Ongoing real-world registry data from Micra shows similar results, whereas Nanostim implantations have been halted due to an unexpected battery malfunction alert in late 2016. More data on device retrieval has become available, along with other strategies for end-of-life management. Leadless pacemakers have emerged in clinical use based on their clinical outcomes and safety profile. These devices are expected to further revolutionize the field of cardiac pacing.

P406Potential local inflammation in individuals implanted with a leadless pacemaker systems: an experimental in vitro study

P406Potential local inflammation in individuals implanted with a leadless pacemaker systems: an experimental in vitro study

Fundamental Characterization of Conductive Intracardiac Communication for Leadless Multisite Pacemaker Systems.

A new generation of leadless cardiac pacemakers effectively overcomes the main limitations of conventional devices, but only offer single-chamber pacing, although dual-chamber or multisite pacing is highly desirable for most patients. The combination of several leadless pacemakers could facilitate a leadless multisite pacemaker but requires an energy-efficient wireless communication for device synchronization. This study investigates the characteristics of conductive intracardiac communication between leadless pacemakers to provide a basis for future designs of leadless multisite pacemaker systems. Signal propagation and impedance behavior of blood and heart tissue were examined by in vitro and in vivo measurements on domestic pig hearts and by finite-element simulations in the frequency range of 1 kHz to 1 MHz. A better signal transmission was obtained for frequencies higher than 10 kHz. The influence of a variety of practical parameters on signal transmission could be identified. A larger distance between pacemakers increases signal attenuation. A better signal transmission is obtained through larger inter-electrode distances and a larger electrode surface area. Furthermore, the influence of pacemaker encapsulation and relative device orientation was assessed. This study suggests that conductive intracardiac communication is well suited to be incorporated in leadless pacemakers. It potentially offers very low power consumption using low communication frequencies. The presented technique enables highly desired leadless multisite pacing in near future.

Impact of operator experience and training strategy on procedural outcomes with leadless pacing: Insights from the Micra Transcatheter Pacing Study.

Leadless pacemaker systems have been designed to avoid the need for a pocket and transvenous lead. However, delivery of this therapy requires a new catheter-based procedure. This study evaluates the role of operator experience and different training strategies on procedural outcomes. A total of 726 patients underwent implant attempt with the Micra transcatheter pacing system (TPS; Medtronic, Minneapolis, MN, USA) by 94 operators trained in a teaching laboratory using a simulator, cadaver, and large animal models (lab training) or locally at the hospital with simulator/demo model and proctorship (hospital training). Procedure success, procedure duration, fluoroscopy time, and safety outcomes were compared between training methods and experience (implant case number). The Micra TPS procedure was successful in 99.2% of attempts and did not differ between the 55 operators trained in the lab setting and the 39 operators trained locally at the hospital (P = 0.189). Implant case number was also not a determinant of procedural success (P = 0.456). Each operator performed between one and 55 procedures. Procedure time and fluoroscopy duration decreased by 2.0% (P = 0.002) and 3.2% (P < 0.001) compared to the previous case. Major complication rate and pericardial effusion rate were not associated with case number (P = 0.755 and P = 0.620, respectively). There were no differences in the safety outcomes by training method. Among a large group of operators, implantation success was high regardless of experience. While procedure duration and fluoroscopy times decreased with implant number, complications were low and not associated with case number. Procedure and safety outcomes were similar between distinct training methodologies.

P437Analysis of artifact characteristics of leadless pacemaker systems in cardiac MRI: results from an ex vivo model

P437Analysis of artifact characteristics of leadless pacemaker systems in cardiac MRI: results from an ex vivo model

Incidence of Cardiac Perforation With Conventional and With Leadless Pacemaker Systems: A Systematic Review and Meta-Analysis.

Two leadless pacemaker (PM) systems were recently developed to avoid pocket- and lead-related complications. As leadless PMs are implanted with a large delivery catheter, cardiac perforation remains a major safety concern. We aimed to provide a literature review on incidence of cardiac perforation with conventional and with leadless PM systems. A systematic review over the last 25 years for studies reporting data on PM lead perforation was performed. Findings were synthesized descriptively. Where control groups were available, data were meta-analyzed to identify important clinical risk factors. A total of 28 studies comprising 60,744 patients undergoing conventional PM implantation were analyzed. The incidence of lead perforation ranged from 0% to 6.37% (mean 0.82%, weighted mean 0.31%, median of 0.40%). There was no significant difference in perforation risk between atrial and ventricular electrodes (POR 0.72, 95% confidence interval [CI], 0.28-1.87, P = 0.50) and between MRI conditional and conventional leads (POR 5.93, 95% CI, 0.72-48.76, P = 0.10). The use of active fixation leads (POR 4.25, 95% CI, 1.00-17.95, P = 0.05) and utilization of DDD versus VVI PM systems (POR 3.50, 95% CI, 1.48-8.28, P < 0.01) were associated with higher rates of perforation. In the 2 leadless PM studies, the incidence of cardiac perforation was 1.52% for each. PM lead perforation rates vary in individual studies with an overall low incidence. Leadless PMs seem to be associated with a slightly higher perforation risk, most likely reflecting a learning curve effect of this novel technology.

Biotelemetry and Wireless Powering for Leadless Pacemaker Systems

In this letter, we address the telemetry and wireless powering problems associated with the recently invented leadless pacemaker. To overcome the telemetry problem, we propose a conformal spiral type Implantable antenna at Medical Implanted Communication Service (MICS) band. In addition, we also apply the recently proposed midfield wireless power transfer (WPT) technique at 1.5 GHz to avoid the bulky energy storage component. We simulate and experimentally measure the performance of the implantable antenna by using porcine heart tissue. Our research shows that, the implantable antenna and wireless power transfer scheme can be implemented in a leadless pacemaker without any significant coupling between them.

Bradykarde Rhythmusstörungen

Clinically symptomatic bradycardia arrhythmias due to disorders of impulse formation and conduction usually lead to an indication for pacemaker implantation. On the other hand, there are also a number of prognostic indications for pacemaker implantation in asymptomatic patients, but often with a lower class of recommendation. After acute myocardial infarction or cardiac surgery the implantation of a pacemaker may be necessary for the occurrence of bradycardia. Prior to a definitive pacemaker implantation reversible or preventable causes must be investigated and treated. Only for acute treatment of symptomatic bradycardia as a bridging measure drug therapy can be considered. For pacemaker supply various systems are available. We distinguish temporary from permanent systems and one-, two-and three-chamber systems. In addition, leadless pacemaker systems are tested.